


practice makes perfect

by big_wet_cas_eyes



Category: Supernatural
Genre: Canon-Typical Violence, Episode: s08e17 Goodbye Stranger, First Kiss, M/M
Language: English
Status: Completed
Published: 2021-02-01
Updated: 2021-02-01
Packaged: 2021-03-18 16:27:31
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 777
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29121180
Author URL: https://archiveofourown.org/users/big_wet_cas_eyes/pseuds/big_wet_cas_eyes
Summary: "We have a mission, Castiel. At some point that mission will require you to kill Dean Winchester," Naomi says, "for the good of Heaven."His eyes go wide with surprise. "I can't. I won't," Castiel says defiantly."You can, and you will, Castiel," she replies, voice cold. "But I knew you would resist, which is why we're going to practice."-----The first time Castiel kills Dean.
Relationships: Castiel/Dean Winchester
Comments: 8
Kudos: 41





	practice makes perfect

**Author's Note:**

> Written for [starrynightdeancas](https://starrynightdeancas.tumblr.com/post/640512697270747136/the-time-has-finally-arrived-here-to-announce-the)'s 2k follower celebration on tumblr
> 
> Day 4 Prompt: **Firsts**. Listen... this was probably supposed to be a fluffy prompt. I had every intention of making it fluffy. It is not even a little bit fluffy.
> 
> [tumblr link](https://big-wet-cas-eyes.tumblr.com/post/641878415351414784/firsts-day-4-of-starrynightdeancas-s-2k)

"We'll start with a tough one, Castiel. Something tells me you'll have to practice, so we might as well begin with a possible worst case scenario," Naomi says, voice clear and firm.

"I don't understand. What am I practicing?" Castiel asks. He looks around, not sure where he is or how he got here. He knows he's in Heaven, but everything is unfamiliar here.

"We have a mission, Castiel. At some point that mission will require you to kill Dean Winchester," she says, "for the good of Heaven."

His eyes go wide with surprise. "I can't. I won't," Castiel says defiantly. 

"You can, and you will, Castiel," Naomi replies, voice cold. "But I knew you would resist, which is why we're going to practice." 

A wind gushes through the room and Castiel finds himself standing inside a warehouse, no longer sitting at a desk. He looks around, studying the space. White. Sterile. They're still in Heaven. 

"You will stay here and practice until you are ready," Naomi explains. "We have created copies that will realistically model what it will be like to kill the real Dean Winchester. We've accounted for all possibilities of how he will respond." She looks directly at Castiel when she finishes with, "As I said, I chose this first iteration to be particularly difficult for you. That way we will know how much… assistance you will require. We can revisit this scenario later as well, to make sure you're ready."

"What do you mean 'difficult'?" Castiel asks, slowly forming the air quotes around the word. 

"I think you will figure it out, Castiel," Naomi says before she vanishes. 

The scene around him shifts slightly and he almost feels as if he's on Earth, but he can feel that he isn't. He spots Dean from across the room. He's looking right at Castiel, eyes full of fear.

A ringing inside his brain screams at him to cross over to Dean and hurt him. To kill him. He tries to fight it, but before he knows it, he's crossing the room. 

Dean's backing away from him, unarmed and hands up. He's scared. He's looking right at Castiel and he's scared. "Cas, don't do this." It comes out quietly. His voice sounds as scared as he looks. 

Castiel punches him in the stomach and Dean immediately crumbles to the floor. Castiel's eyes sting with tears, but the ringing in his head keeps screaming at him to _hurt him, kill him, hurt him, kill him._ He tries to fight it, but he can't. 

His fist strikes Dean again and again, incoherent babbling and blood spilling from Dean's lips. His face is bruised and broken, eyes wet and staring up at Castiel. He's not even trying to fight back. Each hit causes physical pain to Castiel beyond the ache in his knuckles. When he strikes Dean hard enough that he curls up into a ball, the pain slams back into Castiel harder than ever, momentarily silencing the ringing in his ears. He stares at Dean and sees the moment Dean recognizes that something has changed.

"Cas, please…" Dean whispers. It's quiet, like speaking any louder would cause him too much pain. "Please don't do this."

"Dean," Castiel says, voice breaking. He falls to his knees and cradles Dean's head in his hands. "I'm so sorry, Dean. I can't stop it. I don't know how to stop it." 

"Fight it," Dean pleads. "I need you." 

Tears prickle in Castiel's eyes. "Dean, I'm so sorry." He closes his eyes, concentrating to heal Dean. When he opens them, Dean is still covered in blood, one eye swollen shut. "I can't heal you… I'm trying…" Castiel says, frantic.

"I know, Cas. I know," Dean says, tears streaming down his face. "It's okay. Just… kiss me. If I'm going to die, don't let me die without kissing you first. Please…"

Castiel leans down and presses his mouth gently to Dean's. Blood clings to Castiel's lips when they meet Dean's split lip. The tears finally spill out of his own eyes. When he pulls away, he sees Dean's face, now streaked with both of their tears. The blood coating his face is now smeared around his mouth. He looks broken, but still beautiful. Still Dean Winchester. 

"Cas, I love—"

Castiel doesn't hear the end of his sentence. The ringing sound is back, shrieking in his head louder than ever. He can't hear anything else, not even his own inner thoughts screaming at him that he can't hurt Dean. 

It's as if he's watching the scene play out from above when he lifts the angel blade above his head and slams it into Dean's heart. 


End file.
